The deterioration of coffee, i.e. its acquisition of an "old" or "stale" taste and loss of aroma is due primarily to oxidation. This concept was introduced by the prior of the aforesaid copending applications and reference may be had thereto for a complete background discussion. The latter of the aforesaid copending applications discloses method and apparatus for dispensing coffee from a conventional coffee maker while maintaining the same isolated from atmosphere to preserve the taste and aroma of freshly brewed coffee over extended periods of time which may be measured in days rather than hours. The disclosures in both of the aforesaid applications have been concerned with the preservation of coffee in, and dispensing of coffee from, containers which are positively sealed to preclude any admixture or ingress of atmosphere to the coffee.
Subsequent experiments have shown that if surface area exposure of a contained quantity of coffee is kept small in comparison to the volume of contained coffee the desired result of preserving the freshly brewed taste and aroma may yet be achieved, albeit over a shorter period of time than is possible with a totally sealed quantity of coffee. The pot life or time period within which a heated pot of coffee remains palatable is generally considered to be approximately one hour. Any substantial extension of this pot life has the obvious advantage of reducing coffee wastage and subsequent preparation time of a "fresh pot".
The present invention differs from the coffee makers disclosed and claimed in the latter of the aforesaid co-pending applications in that the present invention is primarily concerned with limiting surface area exposure of the contained coffee as opposed to positively excluding all contact with atmosphere external of the coffee maker.